What is the difference between a NAS and a SAN? So that is the topic of this post. So we’ll first talk about what a NAS is.
NAS stands for network-attached storage. If you wanted to store data in a centralized location, where it can be accessed from all of your devices on your network, you could do this by using a network-attached storage device. And NAS is a storage device that is used for storing data. And it doesn’t do anything else besides storing data. Now, typically, a NAS is a box that will have multiple hard drives in a RAID configuration for redundancy.
And it also has a network interface card that will directly attach to a switch or router so that the data can be accessed over a network. Then once it’s on the network, it can be accessed from other devices, such as desktops, laptops, and servers. And it can be accessed as a shared drive.
NAS is typically used in homes. And they are also used in small to medium-sized businesses. But one of the main disadvantages with a NAS is that it has a single point of failure. So as an example, let’s say if a component fails, such as if the power supply fails on the NAS, then all of the other devices will not be able to access its data.
Now, a SAN or storage area network is a specialized high-speed network that stores and provides access to large amounts of data. So basically, it’s a dedicated network that’s used for data storage. And this network consists of multiple disk arrays, switches, and servers.
Because SAN has more than one of these devices, a SAN is fully tolerant. And the data is also shared among several disk arrays. So if a switch or discourage or if a server goes down, the data can still be accessed.
And when a server accesses the data on a SAN, it accesses the data as if it was a local hard drive, because that’s how operating systems recognize a SAN.
It’s recognized as a local hard drive rather than a shared network drive, like in a NAS. SAN is also highly scalable because adding more storage space can easily be done without interruption on the network. So as stated before, a SAN is a high-speed network. And that’s because, in a SAN, all the devices are interconnected, meaning that all other devices are connected to each other. And they are interconnected using fiber channels. Fiber channel has speeds above 2 gigabits per second, all the way up to 128 gigabits per second.
So the fiber channel is extremely fast, and it’s also very expensive. And most SANs today use fiber channel, but also as an alternative to the fiber channel. Some SAN use iSCSI instead, which is a cheaper alternative to fiber channel, but it’s also not as fast as fiber channel.
Now, one of the main reasons for using a SAN is because SAN is not affected by network traffic such as bottlenecks that can happen in a local area network. And this is because SANs aren’t a part of a local area network. SANs are partitioned off.
It’s basically a network all by itself. And other reasons for SAN. As I mentioned before, SAN is highly scalable, and they are also very redundant. And also, as you might have guessed, SANs are not cheap. They come at a very high cost, which is why large companies and large organizations mainly use them.